In January 1962, when I was the author of one and a half unperformed plays, I attended a student production of The Birthday Party at the Victoria Rooms in Bristol. Just before it began, I realised that Harold Pinter was sitting in front of me. Thereupon I became distracted by the necessity of speaking to him. I needed an opening gambit, and started to consider several. So, when The Birthday Party – to which I gave as much of my attention as I could spare – was over, I tapped him on the shoulder, and – I'm sorry to say – spoke to him as follows: "Are you Harold Pinter or do you only look like him?" He turned round and I got an early inkling of Harold Pinter's unflinching, unswerving gaze. He said, "What?" I don't remember any more. Perhaps I fainted. I want to explain why in 1962 the author of The Birthday Party fascinated and intimidated me. In the preceding few years I had seen all kinds of plays and the art of the playwright, it seemed to me, was to order the flow of information from the stage to the audience. The writer could divert, distort or delay the information, dislocate it in time or space, or put it in iambic pentameters, but the information was there. Plays were not ignorant about themselves. But Pinter did something so counterintuitive it could not be thought of as a technique, it could only be thought of as an accommodation of his nature. He disavowed his right to a large part of the information over which the playwright is supposedly in control.

This is, on the face of it, ridiculous. After all, Pinter had invented The Birthday Party, he invented Stanley, so what was there to stop him inventing Stanley's backstory? The morning after I saw The Birthday Party, I went along to a post-play discussion in which Pinter reluctantly participated, and I wrote down everything he said, because I was reporting on the discussion. One of the things he said was, "If the past can be obscure, why not the present?"

Indeed, why not? Other people's lives come at us without a backstory most of the time. The present is like that. It's only in the theatre that we expect to be filled in on everything we witness. Because theatre is a story-telling art form, we feel entitled to assume that the playwright got there before we got there. The Birthday Party was a problem play because it was as if the author had arrived late. In fact, he seemed to have got there only when we got there, and knew no more than we did. Such was the Pinter play and if it became less of a problem it was because Pinter loosened our expectations of an art form which had been telling us stories for centuries.

The first time I saw Old Times – when it was brand new – I was frustrated by it. I wanted to know the answer, the historical truth: what really and truly did happen, back then, before we arrived? Which memory was the true one? How perverse not to let on! But it seemed the author didn't know either. The second time I saw it, in a new production much later, it was no longer a problem. I no longer had the feeling that the play narrowed the story-telling art by the margin of what it withheld or cancelled out. Now I had the feeling that the play had deepened it, and, because Pinter himself didn't know where the story bottomed out, the depth seemed infinite. Pinter was still arriving late at his own stories. But by then I – like many people, I suspect – after beginning by not knowing whether I was overestimating or underestimating him, had just thrown my hat in the air and gone with him. "What I write", Harold told the students that morning in Bristol, "is not obligated to anything but itself." The word that comes to me now is "honesty".

Honesty is seldom ingratiating and often discomfiting. With Harold, when it is applied to (and I'm quoting now from his Nobel prize speech) "a fierce intellectual determination … to define the real truth of our lives and our societies," the trope that comes to mind is "blazing honesty". If Harold knew what has happened and continues to happen in our lives and societies even in the short time since his death he would be incandescent.

I want to make a point which I can only make by saying something about my life. It's the backstory.

I was born Tomas Straussler in Moravia, in what is now the Czech Republic, in 1937. My father was one of seven Jewish doctors working at the Bata hospital in Zlin. In 1939, he and my mother and their two small children were moved to a place of greater safety, which was Singapore. In early 1942 when the Japanese were invading, my mother and my brother and I were put on one of the last boats, bound, I believe, for Australia, but were diverted by the war at sea, and we finally got put ashore in Bombay. My father, we learned much later, got away just as Singapore fell, but was killed when his boat was attacked. After the war my mother married a British army officer, Kenneth Stoppard, who brought us from India to England in 1946 when I was eight. My four grandparents and much of my family of my parents' generation died in the camps.

Half the point I want to make is that I have had a charmed life. I was whisked out of the way of the Nazis, bundled out of the way of the Japanese army, and, after a safe and happy four years in India, found myself in England instead of returning to Czechoslovakia in good time to grow up under communism. But I haven't made my point even yet. I wasn't merely safe, I was in the land of tolerance, fair play and autonomous liberty, of habeas corpus, of the mother of parliaments, of freedom of speech, worship and assembly, of the English language. I didn't make this list when Iwas eight, but by 18 I would have added the best and freest newspapers, forged in the crucible of modern liberty, and the best theatre. When I was 19 there occurred the Hungarian revolution, and my first interest was in how the story was being covered. On my 23rd birthday I panicked because I'd written nothing except journalism, and wrote a derivative play. When I was 31, Russian tanks rolled into Prague, and my wife got angry with me because I was acting English and not Czech. She was right. I didn't feel Czech. I had no memory of Czechoslovakia. I condemned the invasion from the viewpoint of everything I had inherited at the age of eight, including my name. During all that time, I had never been without a bed, or clothes to put on, or food on the table, or without medicine when I was sick, or a school desk to sit at. As I grew up I never had to put on a uniform except as a boy scout. As a journalist and writer I had never been censored or told what to write. As a citizen I never had to fear the knock at the door. The second half of the point I want to make is that if politics is not about giving everybody a life as charmed as mine, it's not about anything much.

Perhaps you will recall that in the summer of 1968, England had its dissidents, too. Thousands of young people of student age, egged on by not a few of their seniors including some of my friends, occupied buildings and took to the barricades to overthrow the existing order. The disdain of the revolutionaries for bourgeois democracy, aka "fascism", was as nothing compared to my disdain for the revolutionaries. They were living in the same England, as a birthright, as I was living in as an accident of history. I thought I knew censorship when I saw it, and repression when I saw it, and I didn't think the freedom to publish exciting manifestoes calling for an end to censorship and repression suggested either. In Moscow five Soviet citizens stood in Red Square with banners to protest the invasion of Czechoslovakia. They were arrested within minutes, and sentenced to exile and hard labour. Circumspice.

Candide had nothing on me. My mantra was: abuses at home were failures in the system; abuses in Russia were the system in perfect working order. The world had polarised for me. You could either have a system where only the state could have a newspaper or you could have a system where any millionaire could have one. Twelve days after the Moscow five were beginning their sentences, UK News Ltd, owned by Rupert Murdoch, entered the battle to buy the News of the World.

I don't come here as an apostate. There is no country in the world I would rather be living in, no country where I would feel safer. Looking at myself shifting in regress 20, 30, 40 years ago, I can see what I was understating and what I was not understating. Until I read Isaiah Berlin, I didn't know I could put a name to each: positive freedom and negative freedom. I had little reverence for positive freedom, the proactive freedom promised by a centralised state; freedom from unemployment, say, or freedom from exploitation by private landlords; or from vulgarity by newspapers, for that matter. Such freedom was concomitant with the withdrawal of negative freedom whose value, I thought then and think now, cannot be overstated: autonomous freedom, the freedom to think for oneself, to use one's discretion, to name things for what they are and not for what they purport to be, to apply common sense, and common humanity.

As it happened, positive freedom in the USSR meant empty shops, rubbish goods and rubbish lives for millions, but that was not the point for me, that was not the dystopia. The horror was the loss of personal responsibility, of personal space in the head, the loss of autonomy, of the freedom to move freely, and the ultimate Orwellian nightmare which is not to know what you have lost. In Nadezhda Mandelstam's memoirs she tells of a group of friends discussing the case of a one-legged war veteran who was given the special privilege of moving his abode across the country, so as to live closer to his sister. The group of friends wondered whether such permission would have been granted in the west. Mrs Mandelstam explained to them that in the west anybody could live anywhere, even if they had two legs. They couldn't get their heads round it. They were intelligentsia, and they didn't know what was lost. I was much struck by that story in Mrs Mandelstam's book. It was the touchstone of totalitarianism for me. I kept it in my pocket like a pebble to remind me of what we had to fear, to defend against, and it was also a rock on which I founded my sense of comfortable national superiority.

I will spare you my rite of passage into a world that was not polarised but fractal, and my obsequies over the England we have mislaid. I'll just mark the place with a list, incomplete and in no particular order. Here goes.

We are selling the family silver, by which I mean the family honour. I began in newspapers, and I revered them. Perhaps I romanticised them. A journalist photographer in one of my plays says "I've been around a lot of places. People do awful things to each other. But it's worse in places where everybody is kept in the dark. It really is. Information is light." So my other mantra on human rights was: a free press makes all the other freedoms possible.

When the phone-hacking story broke, a former newspaper executive said it was just a case of a rogue reporter. When I read that, I knew this wasn't a bad cough, it was cancer. Nobody could hazard something so unlikely without reason to believe that it would be colluded in by others. The nexus of politicians, police and newspaper executives, the poison fruit of, respectively, fear, corruptibility and remorseless commercial competition, was a fall from grace at the very heart of the freedoms hard-won long before I was a schoolboy agog with pride at being British. Had it not been for a handful of reporters on the Guardian, who had a place to stand, would that triple nexus ever have been levered apart, given the politicians' fear of the press, the goalkeeper's fear of the penalty? As the denials unravelled, only the Guardian, the Financial Times and the Independent were keeping the story alive until it could not be ignored.

Honest and brave journalism has not ceased, here or elsewhere. Because I believe in it and consider it vital where charmed lives are not the norm, I am proud to share the PEN/Pinter prize with the Belarusan journalist Iryna Khalip, who knows what it is to be beaten and incarcerated for telling truths, in her case for reporting in defiance of the regime of the dictator Alexander Lukashenko. Iryna is a correspondent in Belarus for the independent Moscow newspaper Novaya Gazyeta. Out of jail now, and no longer under house arrest but under constant surveillance by the KGB, Iryna continues her insightful reportage for Novaya Gazyeta on the knife-edge of self-incrimination and re-arrest. I salute her courage and her example; she is the reporter I wanted to be.

I met Iryna in Minsk eight years ago. I was there for only four days. Afterwards I wrote an article about my visit. In Minsk I'd gone to talk to a film-maker who had made a documentary poking fun at Lukashenko. It was shown on television in Germany and France, and two days after that two men jumped him at his front door and left him unconscious and with a broken leg. His name was Yury Khashchevatskiy. I talked to him in his flat. He showed me his film.

My article ended. "I do my bit to Khashchevatskiy about how uncomfortable it feels to be a privileged visitor watching his film with him, knowing that soon I'll be on a plane home, where I can publicly call the prime minister a liar and a criminal if I want to. He lights up another Belarusan Kent and says, 'The fact that you can call your prime minister a liar and a criminal is not his virtue, it is your virtue, the virtue of your people.'"

Soon after I returned home, an elderly man, Walter Wolfgang, was forcibly ejected by stewards from a Labour party conference meeting for heckling the foreign secretary, Jack Straw, who was defending the decision to invade Iraq. The ejection of Mr Wolfgang was a shocking little incident that got enormous coverage. Four days later, on a Saturday, my article on Belarus, with my interview with Yury Khashchevatskiy, was published in the Guardian. On the Monday I received a postcard from Harold. It said, "Ho Ho!"

• This is an edited extract from Circumspice, the PEN/Pinter prize lecture 2013.